Head Gasket Blown ???

[sticky nicky]

Hi all,

I have a 1993 NA 1.8 ltr and I think I have a blown head gasket or at worst a cracked head or block

When I start the car from cold, not always but mostly, I get alot of white smoke coming from the exhaust. It seems ok when it has warmed up but I havent dríven it far since this has started happening. I have looked at the oil filler cap and it looks ok with no signs of sludge as yet. Before I started the car this morning I looked at the coolant level and it had dropped, it was at least below the level of the top of the core. When I started it with the cap of the level of the coolant came up quite quickly and there was alot of small air bubbles bubbling in the coolant. Is this because there is a problem with the gasket, head etc. or is it because I was running it with cap off and the level of coolant was too low and it was bubbling beacuse the pressure was building in the system????

Just a thought, If I can find a spark plug remover small enough to get into and down into the hole I will remove them and see if there is any sign of water on the plugs. Will this show anything ?????

On the short runs I have done in the car there seems to no loss of power and no hesitation under acceleration. There is a splater of water coming from the exhaust when reving the engine but I guess this is just condensation when it is warming up from cold ????

If it is the head gasket or head does anyone have any idea roughly how much this will cost to get repaired.

Can anyone recommend a good trustworthy MX5 mechanic in Perth preferably south of the river.

Thanks for your help in advance

[manga_blue]

Sorry. This doesn't sound good. Did you boil it?

The presence the fine bubbles in the coolant is a strong indicator of a blown head gasket. It means gases are travelling from the combustion chambers across the head gasket and into the cooling system. If the cooling system is pressurised then there's a possibility that coolant is travelling the other way as well, causing coolant loss out the exhaust. Also if you have ethylene glycol (the green stuff) in the coolant then there's often a sickly sweet smell from the exhaust.

Best to get it to a workshop. Cylinder compression and radiator pressure tests there will take out the guesswork.

[sticky nicky]

No i didnt boil it.

Thanks for your help, any other opinions or names of good mx mechanics in Perth?

[xmx106]

The white smoke on start up and water coming from the exhaust is not a good sign and is a clear symptom of a head gasket leak.
If you remove your spark plugs and you find that one or two are a different colour from the rest, then that is a pointer to the problem.
A compression test may then show one or two cylinders are down, these will be the cylinders with the different coloured spark plugs.
With all the plugs removed you can crank over the engine while holding a white rag down in the bottom of the spark plug hole with a srew driver, the rag will show up a wet dirty patch if water has entered the cylinder, compared to a dry oily mark.
Thats about all you can do at home other than look for any other external leak that would explain the coolant loss.
A mechanic can do a pressure test on the coolant system and can check the radiator water with a chemical test kit to identify exhaust gases.
These engines are very tough, you wont have cracked the block and you are extremely unlikely to have cracked the head unless you have had a major overheat with no water in the radiator, you may have just blown the head gasket, which will require a new gasket possibly a light skim of the head if it isnt flat. While you are doing this job, change the water pump and the timing belt if it hasnt been done in the last 100,000 klm's.
I am in Perth, the only engineering place i have been to for this sort of work was Davilac engineering at
3 Hamilton Road
Hamilton Hill WA 6163, Australia
(08) 9335 3781
I did a cylinder head gasket on a ford laser wagon, it had a SOHC B6 mazda engine, they didnt do the engine work i did it myself (marine engineer), but they skimmed the head and supplied me with a cheap gasket kit. I am unsure how much they will do, but if they are not up for a full mechanical diagnosis they could recommend one of the mechanics they deal with regularly in the area.
I am sure some other WA guys will chime in with a mechanic you can trust.
Best of luck

[ak_perth]

I can recommend a garage. KYP in Welshpool

http://kyp.com.au/kyp/

Ask for Steve, he's very good. He knows MX5's inside out and he's a very nice guy.

Tell him Al with the shiny red NA recommended him.

Cheers

AK

[lukearama]

re spark plug remover:

if you have you original tool kit you will find one in that. Its a long pipe with a hex at one end and the hole for a screw driver at the other.

This will be a head rebuild for sure. you will need a VRS set a water pump a cylinder head rebuild those parts alone will set you back atleast $1200 on a good day. Expect a heap more for labour. While your at it get you piston removed re-ring and hone your bores checking block to factory specs. add another $600 for this most likely more.

SO for about $2K you should have a brand new engine that will give you another 100,000km of reliability. Your alternative is a second hand engine..

best of luck mate.

[xmx106]

I wouldnt go as far as "lukearama" suggests above, it all depends on how may klm's your car has done, suggesting a piston pull and re-ring requires the engine to be removed and at this point you only have a possible head gasket issue, which has maybe blown through between one cylinder and a cooling water port between the head and the block. You say you have lost no power and it goes ok when warmed up, the most common head gasket blow out is in the narrow section between two cylinders, this results in lost of compression on two cylinders and you will know about it, loss of power is considerable and even starting the car is sometimes not possible. You need a good mechanic who will not go overboard and spend your money unnecessarily, as i said before these engines are tough, if your head is no longer flat a light skim will fix that, your valves may need a light re-lapping, but thats about it, a gasket kit is maybe between $120 / $150 depending on supplier.
The head skim is about $80 and when the head is off they can test how good the valve seats are by appling a vacuum to the ports seeing if the vacuum holds or leaks off quickly, this will cost you maybe $25 for their time but saves you heaps of unnecessary costs on head and valve work. The biggest cost is the mechanics labor.
Talk to the mechanic, tell him your budget is tight, the car runs ok, but this coolant loss is your concern, he will do the basics first to find the problem, a compression test will tell you how good your engine is and pinpoint the issue.

[sticky nicky]

Ok, thanks for your comments guys, hopefully its just the head gasket, off to the mechanic next week.

[sticky nicky]

(copied from my compression test post)

Hi guys,

Yeh apparently I was loosing coolant from the lower radiator hose due to a faulty seal around the clamp which he found by doing a pressure test. The white smoke is almost non existant on start up now. In KYP's opinion it is probably due to a faulty oil ring on the cylinder with low compression and/or faulty valve stem seals which Im not too worried about at the moment, my main concern was the loss of coolant and whether the two were related.
So all in all I am happy that I dont have a huge job to do at the moment, the cars running great. I guess in time if the smoke gets worse I will have to do something about it.
Time to get my road/track tyres which I had put on hold

[bootz]

Club meet at Wheels world on 11th.

[sticky nicky]

Yeh I saw that, Ive endend up getting some Achillies 123s, same as Russell. Got them for $600 fitted (4) Had planned to go through wheels world but these just came up so went for them at such a cheap price. Hopefully have a little more grip now than my road tyres.